From: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Date: Fri, 1 Oct 2021 15:03:43 +0200
Subject: bpf/tests: Add more tests for ALU and ATOMIC register clobbering
Patch-mainline: v5.16-rc1
Git-commit: e2f9797b3c7396065ca3bc9f223225ca63c1e2bd
References: jsc#PED-1377
This patch expands the register-clobbering-during-function-call tests
to cover more all ALU32/64 MUL, DIV and MOD operations and all ATOMIC
operations. In short, if a JIT implements a complex operation with
a call to an external function, it must make sure to save and restore
all its caller-saved registers that may be clobbered by the call.
Signed-off-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20211001130348.3670534-6-johan.almbladh@anyfinetworks.com
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
---
lib/test_bpf.c | 267 ++++++++++++++++++++++++++++++++++++++++++---------------
1 file changed, 197 insertions(+), 70 deletions(-)
--- a/lib/test_bpf.c
+++ b/lib/test_bpf.c
@@ -3746,76 +3746,6 @@ static struct bpf_test tests[] = {
},
{
/*
- * Register (non-)clobbering test, in the case where a 32-bit
- * JIT implements complex ALU64 operations via function calls.
- * If so, the function call must be invisible in the eBPF
- * registers. The JIT must then save and restore relevant
- * registers during the call. The following tests check that
- * the eBPF registers retain their values after such a call.
- */
- "INT: Register clobbering, R1 updated",
- .u.insns_int = {
- BPF_ALU32_IMM(BPF_MOV, R0, 0),
- BPF_ALU32_IMM(BPF_MOV, R1, 123456789),
- BPF_ALU32_IMM(BPF_MOV, R2, 2),
- BPF_ALU32_IMM(BPF_MOV, R3, 3),
- BPF_ALU32_IMM(BPF_MOV, R4, 4),
- BPF_ALU32_IMM(BPF_MOV, R5, 5),
- BPF_ALU32_IMM(BPF_MOV, R6, 6),
- BPF_ALU32_IMM(BPF_MOV, R7, 7),
- BPF_ALU32_IMM(BPF_MOV, R8, 8),
- BPF_ALU32_IMM(BPF_MOV, R9, 9),
- BPF_ALU64_IMM(BPF_DIV, R1, 123456789),
- BPF_JMP_IMM(BPF_JNE, R0, 0, 10),
- BPF_JMP_IMM(BPF_JNE, R1, 1, 9),
- BPF_JMP_IMM(BPF_JNE, R2, 2, 8),
- BPF_JMP_IMM(BPF_JNE, R3, 3, 7),
- BPF_JMP_IMM(BPF_JNE, R4, 4, 6),
- BPF_JMP_IMM(BPF_JNE, R5, 5, 5),
- BPF_JMP_IMM(BPF_JNE, R6, 6, 4),
- BPF_JMP_IMM(BPF_JNE, R7, 7, 3),
- BPF_JMP_IMM(BPF_JNE, R8, 8, 2),
- BPF_JMP_IMM(BPF_JNE, R9, 9, 1),
- BPF_ALU32_IMM(BPF_MOV, R0, 1),
- BPF_EXIT_INSN(),
- },
- INTERNAL,
- { },
- { { 0, 1 } }
- },
- {
- "INT: Register clobbering, R2 updated",
- .u.insns_int = {
- BPF_ALU32_IMM(BPF_MOV, R0, 0),
- BPF_ALU32_IMM(BPF_MOV, R1, 1),
- BPF_ALU32_IMM(BPF_MOV, R2, 2 * 123456789),
- BPF_ALU32_IMM(BPF_MOV, R3, 3),
- BPF_ALU32_IMM(BPF_MOV, R4, 4),
- BPF_ALU32_IMM(BPF_MOV, R5, 5),
- BPF_ALU32_IMM(BPF_MOV, R6, 6),
- BPF_ALU32_IMM(BPF_MOV, R7, 7),
- BPF_ALU32_IMM(BPF_MOV, R8, 8),
- BPF_ALU32_IMM(BPF_MOV, R9, 9),
- BPF_ALU64_IMM(BPF_DIV, R2, 123456789),
- BPF_JMP_IMM(BPF_JNE, R0, 0, 10),
- BPF_JMP_IMM(BPF_JNE, R1, 1, 9),
- BPF_JMP_IMM(BPF_JNE, R2, 2, 8),
- BPF_JMP_IMM(BPF_JNE, R3, 3, 7),
- BPF_JMP_IMM(BPF_JNE, R4, 4, 6),
- BPF_JMP_IMM(BPF_JNE, R5, 5, 5),
- BPF_JMP_IMM(BPF_JNE, R6, 6, 4),
- BPF_JMP_IMM(BPF_JNE, R7, 7, 3),
- BPF_JMP_IMM(BPF_JNE, R8, 8, 2),
- BPF_JMP_IMM(BPF_JNE, R9, 9, 1),
- BPF_ALU32_IMM(BPF_MOV, R0, 1),
- BPF_EXIT_INSN(),
- },
- INTERNAL,
- { },
- { { 0, 1 } }
- },
- {
- /*
* Test 32-bit JITs that implement complex ALU64 operations as
* function calls R0 = f(R1, R2), and must re-arrange operands.
*/
@@ -10586,6 +10516,203 @@ static struct bpf_test tests[] = {
{},
{ { 0, 2 } },
},
+ /*
+ * Register (non-)clobbering tests for the case where a JIT implements
+ * complex ALU or ATOMIC operations via function calls. If so, the
+ * function call must be transparent to the eBPF registers. The JIT
+ * must therefore save and restore relevant registers across the call.
+ * The following tests check that the eBPF registers retain their
+ * values after such an operation. Mainly intended for complex ALU
+ * and atomic operation, but we run it for all. You never know...
+ *
+ * Note that each operations should be tested twice with different
+ * destinations, to check preservation for all registers.
+ */
+#define BPF_TEST_CLOBBER_ALU(alu, op, dst, src) \
+ { \
+ #alu "_" #op " to " #dst ": no clobbering", \
+ .u.insns_int = { \
+ BPF_ALU64_IMM(BPF_MOV, R0, R0), \
+ BPF_ALU64_IMM(BPF_MOV, R1, R1), \
+ BPF_ALU64_IMM(BPF_MOV, R2, R2), \
+ BPF_ALU64_IMM(BPF_MOV, R3, R3), \
+ BPF_ALU64_IMM(BPF_MOV, R4, R4), \
+ BPF_ALU64_IMM(BPF_MOV, R5, R5), \
+ BPF_ALU64_IMM(BPF_MOV, R6, R6), \
+ BPF_ALU64_IMM(BPF_MOV, R7, R7), \
+ BPF_ALU64_IMM(BPF_MOV, R8, R8), \
+ BPF_ALU64_IMM(BPF_MOV, R9, R9), \
+ BPF_##alu(BPF_ ##op, dst, src), \
+ BPF_ALU32_IMM(BPF_MOV, dst, dst), \
+ BPF_JMP_IMM(BPF_JNE, R0, R0, 10), \
+ BPF_JMP_IMM(BPF_JNE, R1, R1, 9), \
+ BPF_JMP_IMM(BPF_JNE, R2, R2, 8), \
+ BPF_JMP_IMM(BPF_JNE, R3, R3, 7), \
+ BPF_JMP_IMM(BPF_JNE, R4, R4, 6), \
+ BPF_JMP_IMM(BPF_JNE, R5, R5, 5), \
+ BPF_JMP_IMM(BPF_JNE, R6, R6, 4), \
+ BPF_JMP_IMM(BPF_JNE, R7, R7, 3), \
+ BPF_JMP_IMM(BPF_JNE, R8, R8, 2), \
+ BPF_JMP_IMM(BPF_JNE, R9, R9, 1), \
+ BPF_ALU64_IMM(BPF_MOV, R0, 1), \
+ BPF_EXIT_INSN(), \
+ }, \
+ INTERNAL, \
+ { }, \
+ { { 0, 1 } } \
+ }
+ /* ALU64 operations, register clobbering */
+ BPF_TEST_CLOBBER_ALU(ALU64_IMM, AND, R8, 123456789),
+ BPF_TEST_CLOBBER_ALU(ALU64_IMM, AND, R9, 123456789),
+ BPF_TEST_CLOBBER_ALU(ALU64_IMM, OR, R8, 123456789),
+ BPF_TEST_CLOBBER_ALU(ALU64_IMM, OR, R9, 123456789),
+ BPF_TEST_CLOBBER_ALU(ALU64_IMM, XOR, R8, 123456789),
+ BPF_TEST_CLOBBER_ALU(ALU64_IMM, XOR, R9, 123456789),
+ BPF_TEST_CLOBBER_ALU(ALU64_IMM, LSH, R8, 12),
+ BPF_TEST_CLOBBER_ALU(ALU64_IMM, LSH, R9, 12),
+ BPF_TEST_CLOBBER_ALU(ALU64_IMM, RSH, R8, 12),
+ BPF_TEST_CLOBBER_ALU(ALU64_IMM, RSH, R9, 12),
+ BPF_TEST_CLOBBER_ALU(ALU64_IMM, ARSH, R8, 12),
+ BPF_TEST_CLOBBER_ALU(ALU64_IMM, ARSH, R9, 12),
+ BPF_TEST_CLOBBER_ALU(ALU64_IMM, ADD, R8, 123456789),
+ BPF_TEST_CLOBBER_ALU(ALU64_IMM, ADD, R9, 123456789),
+ BPF_TEST_CLOBBER_ALU(ALU64_IMM, SUB, R8, 123456789),
+ BPF_TEST_CLOBBER_ALU(ALU64_IMM, SUB, R9, 123456789),
+ BPF_TEST_CLOBBER_ALU(ALU64_IMM, MUL, R8, 123456789),
+ BPF_TEST_CLOBBER_ALU(ALU64_IMM, MUL, R9, 123456789),
+ BPF_TEST_CLOBBER_ALU(ALU64_IMM, DIV, R8, 123456789),
+ BPF_TEST_CLOBBER_ALU(ALU64_IMM, DIV, R9, 123456789),
+ BPF_TEST_CLOBBER_ALU(ALU64_IMM, MOD, R8, 123456789),
+ BPF_TEST_CLOBBER_ALU(ALU64_IMM, MOD, R9, 123456789),
+ /* ALU32 immediate operations, register clobbering */
+ BPF_TEST_CLOBBER_ALU(ALU32_IMM, AND, R8, 123456789),
+ BPF_TEST_CLOBBER_ALU(ALU32_IMM, AND, R9, 123456789),
+ BPF_TEST_CLOBBER_ALU(ALU32_IMM, OR, R8, 123456789),
+ BPF_TEST_CLOBBER_ALU(ALU32_IMM, OR, R9, 123456789),
+ BPF_TEST_CLOBBER_ALU(ALU32_IMM, XOR, R8, 123456789),
+ BPF_TEST_CLOBBER_ALU(ALU32_IMM, XOR, R9, 123456789),
+ BPF_TEST_CLOBBER_ALU(ALU32_IMM, LSH, R8, 12),
+ BPF_TEST_CLOBBER_ALU(ALU32_IMM, LSH, R9, 12),
+ BPF_TEST_CLOBBER_ALU(ALU32_IMM, RSH, R8, 12),
+ BPF_TEST_CLOBBER_ALU(ALU32_IMM, RSH, R9, 12),
+ BPF_TEST_CLOBBER_ALU(ALU32_IMM, ARSH, R8, 12),
+ BPF_TEST_CLOBBER_ALU(ALU32_IMM, ARSH, R9, 12),
+ BPF_TEST_CLOBBER_ALU(ALU32_IMM, ADD, R8, 123456789),
+ BPF_TEST_CLOBBER_ALU(ALU32_IMM, ADD, R9, 123456789),
+ BPF_TEST_CLOBBER_ALU(ALU32_IMM, SUB, R8, 123456789),
+ BPF_TEST_CLOBBER_ALU(ALU32_IMM, SUB, R9, 123456789),
+ BPF_TEST_CLOBBER_ALU(ALU32_IMM, MUL, R8, 123456789),
+ BPF_TEST_CLOBBER_ALU(ALU32_IMM, MUL, R9, 123456789),
+ BPF_TEST_CLOBBER_ALU(ALU32_IMM, DIV, R8, 123456789),
+ BPF_TEST_CLOBBER_ALU(ALU32_IMM, DIV, R9, 123456789),
+ BPF_TEST_CLOBBER_ALU(ALU32_IMM, MOD, R8, 123456789),
+ BPF_TEST_CLOBBER_ALU(ALU32_IMM, MOD, R9, 123456789),
+ /* ALU64 register operations, register clobbering */
+ BPF_TEST_CLOBBER_ALU(ALU64_REG, AND, R8, R1),
+ BPF_TEST_CLOBBER_ALU(ALU64_REG, AND, R9, R1),
+ BPF_TEST_CLOBBER_ALU(ALU64_REG, OR, R8, R1),
+ BPF_TEST_CLOBBER_ALU(ALU64_REG, OR, R9, R1),
+ BPF_TEST_CLOBBER_ALU(ALU64_REG, XOR, R8, R1),
+ BPF_TEST_CLOBBER_ALU(ALU64_REG, XOR, R9, R1),
+ BPF_TEST_CLOBBER_ALU(ALU64_REG, LSH, R8, R1),
+ BPF_TEST_CLOBBER_ALU(ALU64_REG, LSH, R9, R1),
+ BPF_TEST_CLOBBER_ALU(ALU64_REG, RSH, R8, R1),
+ BPF_TEST_CLOBBER_ALU(ALU64_REG, RSH, R9, R1),
+ BPF_TEST_CLOBBER_ALU(ALU64_REG, ARSH, R8, R1),
+ BPF_TEST_CLOBBER_ALU(ALU64_REG, ARSH, R9, R1),
+ BPF_TEST_CLOBBER_ALU(ALU64_REG, ADD, R8, R1),
+ BPF_TEST_CLOBBER_ALU(ALU64_REG, ADD, R9, R1),
+ BPF_TEST_CLOBBER_ALU(ALU64_REG, SUB, R8, R1),
+ BPF_TEST_CLOBBER_ALU(ALU64_REG, SUB, R9, R1),
+ BPF_TEST_CLOBBER_ALU(ALU64_REG, MUL, R8, R1),
+ BPF_TEST_CLOBBER_ALU(ALU64_REG, MUL, R9, R1),
+ BPF_TEST_CLOBBER_ALU(ALU64_REG, DIV, R8, R1),
+ BPF_TEST_CLOBBER_ALU(ALU64_REG, DIV, R9, R1),
+ BPF_TEST_CLOBBER_ALU(ALU64_REG, MOD, R8, R1),
+ BPF_TEST_CLOBBER_ALU(ALU64_REG, MOD, R9, R1),
+ /* ALU32 register operations, register clobbering */
+ BPF_TEST_CLOBBER_ALU(ALU32_REG, AND, R8, R1),
+ BPF_TEST_CLOBBER_ALU(ALU32_REG, AND, R9, R1),
+ BPF_TEST_CLOBBER_ALU(ALU32_REG, OR, R8, R1),
+ BPF_TEST_CLOBBER_ALU(ALU32_REG, OR, R9, R1),
+ BPF_TEST_CLOBBER_ALU(ALU32_REG, XOR, R8, R1),
+ BPF_TEST_CLOBBER_ALU(ALU32_REG, XOR, R9, R1),
+ BPF_TEST_CLOBBER_ALU(ALU32_REG, LSH, R8, R1),
+ BPF_TEST_CLOBBER_ALU(ALU32_REG, LSH, R9, R1),
+ BPF_TEST_CLOBBER_ALU(ALU32_REG, RSH, R8, R1),
+ BPF_TEST_CLOBBER_ALU(ALU32_REG, RSH, R9, R1),
+ BPF_TEST_CLOBBER_ALU(ALU32_REG, ARSH, R8, R1),
+ BPF_TEST_CLOBBER_ALU(ALU32_REG, ARSH, R9, R1),
+ BPF_TEST_CLOBBER_ALU(ALU32_REG, ADD, R8, R1),
+ BPF_TEST_CLOBBER_ALU(ALU32_REG, ADD, R9, R1),
+ BPF_TEST_CLOBBER_ALU(ALU32_REG, SUB, R8, R1),
+ BPF_TEST_CLOBBER_ALU(ALU32_REG, SUB, R9, R1),
+ BPF_TEST_CLOBBER_ALU(ALU32_REG, MUL, R8, R1),
+ BPF_TEST_CLOBBER_ALU(ALU32_REG, MUL, R9, R1),
+ BPF_TEST_CLOBBER_ALU(ALU32_REG, DIV, R8, R1),
+ BPF_TEST_CLOBBER_ALU(ALU32_REG, DIV, R9, R1),
+ BPF_TEST_CLOBBER_ALU(ALU32_REG, MOD, R8, R1),
+ BPF_TEST_CLOBBER_ALU(ALU32_REG, MOD, R9, R1),
+#undef BPF_TEST_CLOBBER_ALU
+#define BPF_TEST_CLOBBER_ATOMIC(width, op) \
+ { \
+ "Atomic_" #width " " #op ": no clobbering", \
+ .u.insns_int = { \
+ BPF_ALU64_IMM(BPF_MOV, R0, 0), \
+ BPF_ALU64_IMM(BPF_MOV, R1, 1), \
+ BPF_ALU64_IMM(BPF_MOV, R2, 2), \
+ BPF_ALU64_IMM(BPF_MOV, R3, 3), \
+ BPF_ALU64_IMM(BPF_MOV, R4, 4), \
+ BPF_ALU64_IMM(BPF_MOV, R5, 5), \
+ BPF_ALU64_IMM(BPF_MOV, R6, 6), \
+ BPF_ALU64_IMM(BPF_MOV, R7, 7), \
+ BPF_ALU64_IMM(BPF_MOV, R8, 8), \
+ BPF_ALU64_IMM(BPF_MOV, R9, 9), \
+ BPF_ST_MEM(width, R10, -8, \
+ (op) == BPF_CMPXCHG ? 0 : \
+ (op) & BPF_FETCH ? 1 : 0), \
+ BPF_ATOMIC_OP(width, op, R10, R1, -8), \
+ BPF_JMP_IMM(BPF_JNE, R0, 0, 10), \
+ BPF_JMP_IMM(BPF_JNE, R1, 1, 9), \
+ BPF_JMP_IMM(BPF_JNE, R2, 2, 8), \
+ BPF_JMP_IMM(BPF_JNE, R3, 3, 7), \
+ BPF_JMP_IMM(BPF_JNE, R4, 4, 6), \
+ BPF_JMP_IMM(BPF_JNE, R5, 5, 5), \
+ BPF_JMP_IMM(BPF_JNE, R6, 6, 4), \
+ BPF_JMP_IMM(BPF_JNE, R7, 7, 3), \
+ BPF_JMP_IMM(BPF_JNE, R8, 8, 2), \
+ BPF_JMP_IMM(BPF_JNE, R9, 9, 1), \
+ BPF_ALU64_IMM(BPF_MOV, R0, 1), \
+ BPF_EXIT_INSN(), \
+ }, \
+ INTERNAL, \
+ { }, \
+ { { 0, 1 } }, \
+ .stack_depth = 8, \
+ }
+ /* 64-bit atomic operations, register clobbering */
+ BPF_TEST_CLOBBER_ATOMIC(BPF_DW, BPF_ADD),
+ BPF_TEST_CLOBBER_ATOMIC(BPF_DW, BPF_AND),
+ BPF_TEST_CLOBBER_ATOMIC(BPF_DW, BPF_OR),
+ BPF_TEST_CLOBBER_ATOMIC(BPF_DW, BPF_XOR),
+ BPF_TEST_CLOBBER_ATOMIC(BPF_DW, BPF_ADD | BPF_FETCH),
+ BPF_TEST_CLOBBER_ATOMIC(BPF_DW, BPF_AND | BPF_FETCH),
+ BPF_TEST_CLOBBER_ATOMIC(BPF_DW, BPF_OR | BPF_FETCH),
+ BPF_TEST_CLOBBER_ATOMIC(BPF_DW, BPF_XOR | BPF_FETCH),
+ BPF_TEST_CLOBBER_ATOMIC(BPF_DW, BPF_XCHG),
+ BPF_TEST_CLOBBER_ATOMIC(BPF_DW, BPF_CMPXCHG),
+ /* 32-bit atomic operations, register clobbering */
+ BPF_TEST_CLOBBER_ATOMIC(BPF_W, BPF_ADD),
+ BPF_TEST_CLOBBER_ATOMIC(BPF_W, BPF_AND),
+ BPF_TEST_CLOBBER_ATOMIC(BPF_W, BPF_OR),
+ BPF_TEST_CLOBBER_ATOMIC(BPF_W, BPF_XOR),
+ BPF_TEST_CLOBBER_ATOMIC(BPF_W, BPF_ADD | BPF_FETCH),
+ BPF_TEST_CLOBBER_ATOMIC(BPF_W, BPF_AND | BPF_FETCH),
+ BPF_TEST_CLOBBER_ATOMIC(BPF_W, BPF_OR | BPF_FETCH),
+ BPF_TEST_CLOBBER_ATOMIC(BPF_W, BPF_XOR | BPF_FETCH),
+ BPF_TEST_CLOBBER_ATOMIC(BPF_W, BPF_XCHG),
+ BPF_TEST_CLOBBER_ATOMIC(BPF_W, BPF_CMPXCHG),
+#undef BPF_TEST_CLOBBER_ATOMIC
/* Checking that ALU32 src is not zero extended in place */
#define BPF_ALU32_SRC_ZEXT(op) \
{ \